{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T18:44:23Z","timestamp":1791485063066,"version":"4.3.4"},"reference-count":48,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,4,20]],"date-time":"2026-04-20T00:00:00Z","timestamp":1776643200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>The use of cellulosic reinforcement fillers, including cellulose and holocellulose, in the development of sustainable biopolymer composites has become increasingly essential and continues to attract significant attention in the composite industry. This study aimed to improve the structural and morphological characteristics of the polyhydroxybutyrate (PHB) matrix by incorporating cellulosic fillers\u2014namely, \u03b1-cellulose and holocellulose produced via a green processing method\u2014and to evaluate the effect of hemicellulose, present in holocellulose and exhibiting compatibilizing capability, on the overall performance of PHB-based blends. For this, the PHB matrix was first dissolved in chloroform, after which the cellulosic fillers were incorporated into the PHB\u2013chloroform mixtures at 1 wt.% to provide the best homogeneous fiber dispersion. The PHB and cellulosic filler mixtures were blended at 500 rpm with a magnetic mixer for 30 min, and the resulting composite was cast onto a Teflon plate. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy were used to characterize the morphological and structural analysis of the obtained biopolymer-based composites. Thermogravimetric analysis (TG-DTG) was used to determine the thermal properties. The results obtained confirmed the presence of cellulosic fillers in the PHB matrix using FTIR, XRD, and SEM. In contrast to holocellulose, \u03b1-cellulose in the PHB matrix was shown to create a more organized structure. Both \u03b1-cellulose and holocellulose reinforcements were found to have similar effects on the thermal properties of the PHB matrix. Compared with neat PHB, the amount of residual char was found to be more than 36-fold in the sample containing \u03b1-cellulose and more than 41-fold in the sample containing holocellulose.<\/jats:p>","DOI":"10.3390\/polym18080997","type":"journal-article","created":{"date-parts":[[2026,4,20]],"date-time":"2026-04-20T13:22:47Z","timestamp":1776691367000},"page":"997","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Eco-Friendly Polyhydroxybutyrate Composite Films Reinforced with Cellulose and Holocellulose Fibers by the Solvent Casting"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2789-9119","authenticated-orcid":false,"given":"Erol","family":"Imren","sequence":"first","affiliation":[{"name":"Department of Forest Industrial Engineering, Bart\u0131n University, Bart\u0131n 74100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Engin","family":"Kocat\u00fcrk","sequence":"additional","affiliation":[{"name":"Department of Nanotechnology Engineering, Zonguldak B\u00fclent Ecevit University, Zonguldak 67100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7733-2263","authenticated-orcid":false,"given":"Ferhat","family":"\u015een","sequence":"additional","affiliation":[{"name":"Department of Nanotechnology Engineering, Zonguldak B\u00fclent Ecevit University, Zonguldak 67100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2115-8339","authenticated-orcid":false,"given":"Mustafa","family":"Zor","sequence":"additional","affiliation":[{"name":"Department of Nanotechnology Engineering, Zonguldak B\u00fclent Ecevit University, Zonguldak 67100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u015eeyma","family":"\u00d6zl\u00fcsoylu","sequence":"additional","affiliation":[{"name":"Department of Forest Industrial Engineering, Bart\u0131n University, Bart\u0131n 74100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7403-5885","authenticated-orcid":false,"given":"\u00d6zge","family":"\u00d6zg\u00fcrl\u00fck","sequence":"additional","affiliation":[{"name":"Department of Forest Industrial Engineering, Bart\u0131n University, Bart\u0131n 74100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7484-2126","authenticated-orcid":false,"given":"Deniz","family":"Aydemir","sequence":"additional","affiliation":[{"name":"Department of Forest Industrial Engineering, Bart\u0131n University, Bart\u0131n 74100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Turco, R., Santagata, G., Corrado, I., Pezzella, C., and Di Serio, M. (2021). In vivo and post-synthesis strategies to enhance the properties of PHB-based materials: A review. Front. Bioeng. Biotechnol., 8.","DOI":"10.3389\/fbioe.2020.619266"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"375","DOI":"10.1080\/14658011.2023.2202865","article-title":"Taguchi-grey relational analysis in parameter optimisation of green biopolymer composites","volume":"52","author":"Cabuk","year":"2023","journal-title":"Plast. Rubber Compos."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"130745","DOI":"10.1016\/j.ijbiomac.2024.130745","article-title":"The effects of PHB-g-MA types on the mechanical, thermal, morphological, structural, and rheological properties of polyhydroxybutyrate biopolymers","volume":"264","author":"Al","year":"2024","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"e6520","DOI":"10.1002\/pat.6520","article-title":"Biopolymer nanocomposite blends of poly (lactic acid) and polyhydroxybutyrate biopolymers reinforced with cellulose nanofibrils at low loading ratio","volume":"35","author":"Aydemir","year":"2024","journal-title":"Polym. Adv. Technol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1186\/s44316-025-00026-1","article-title":"Compatible composites filaments based on PHB\/starch for 3d printing via fused deposition modeling","volume":"2","author":"Esper","year":"2025","journal-title":"Biotechnol. Sustain. Mater."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Chowdhury, S.G., Chanda, J., Ghosh, S., Pal, A., Ghosh, P., Bhattacharyya, S.K., and Das, A. (2021). Morphology and physico-mechanical threshold of \u03b1-cellulose as filler in an E-SBR composite. Molecules, 26.","DOI":"10.3390\/molecules26030694"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1175","DOI":"10.1177\/00219983211031654","article-title":"Biopolymer nanocomposites of polyhydroxybutyrate and cellulose nanofibrils: Effects of cellulose nanofibril loading levels","volume":"56","author":"Aydemir","year":"2022","journal-title":"J. Compos. Mater."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Adeleye, O.A., Bamiro, O.A., Albalawi, D.A., Alotaibi, A.S., Iqbal, H., Sanyaolu, S., and Menaa, F. (2022). Characterizations of alpha-cellulose and microcrystalline cellulose isolated from cocoa pod husk as a potential pharmaceutical excipient. Materials, 15.","DOI":"10.3390\/ma15175992"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"10649","DOI":"10.1007\/s10570-025-06856-6","article-title":"Microwave-assisted graft copolymerization effects on the material properties of polyhydroxybutyrate-cellulose nanocrystal nanocomposites","volume":"32","author":"Al","year":"2025","journal-title":"Cellulose"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2001118","DOI":"10.1002\/adma.202001118","article-title":"Structural and ecofriendly holocellulose materials from wood: Microscale fibers and nanoscale fibrils","volume":"33","author":"Yang","year":"2021","journal-title":"Adv. Mater."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1319","DOI":"10.1039\/C2SM26932E","article-title":"The role of hemicellulose in nanofibrillated cellulose networks","volume":"9","author":"Arola","year":"2013","journal-title":"Soft Matter"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1893","DOI":"10.1007\/s10570-020-03674-w","article-title":"Cellulose and its derivatives: Towards biomedical applications","volume":"28","author":"Seddiqi","year":"2021","journal-title":"Cellulose"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2016","DOI":"10.1021\/acs.chemrev.2c00477","article-title":"Cellulose: A review of water interactions, applications in composites, and water treatment","volume":"123","author":"Etale","year":"2023","journal-title":"Chem. Rev."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Yang, J., Ching, Y.C., and Chuah, C.H. (2019). Applications of lignocellulosic fibers and lignin in bioplastics: A review. Polymers, 11.","DOI":"10.3390\/polym11050751"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"108083","DOI":"10.1016\/j.polymertesting.2023.108083","article-title":"Challenges and advancement in water absorption of natural fiber-reinforced polymer composites","volume":"124","author":"Mohammed","year":"2023","journal-title":"Polym. Test."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Palmieri, F., Tagoe, J.N.A., and Di Maio, L. (2024). Development of PBS\/Nano Composite PHB-Based Multilayer Blown Films with Enhanced Properties for Food Packaging Applications. Materials, 17.","DOI":"10.3390\/ma17122894"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Vu, D.H., Mahboubi, A., Ferreira, J.A., Taherzadeh, M.J., and \u00c5kesson, D. (2022). Polyhydroxybutyrate-Natural Fiber Reinforcement Biocomposite Production and Their Biological Recyclability through Anaerobic Digestion. Energies, 15.","DOI":"10.3390\/en15238934"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"e20220390","DOI":"10.1590\/1980-5373-mr-2022-0390","article-title":"Processing biodegradable blends of hemicellulose with polyhydroxybutyrate and poly (lactic acid)","volume":"26","author":"Mendes","year":"2023","journal-title":"Mater. Res."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Usurelu, C.D., Badila, S., Frone, A.N., and Panaitescu, D.M. (2022). Poly (3-hydroxybutyrate) nanocomposites with cellulose nanocrystals. Polymers, 14.","DOI":"10.3390\/polym14101974"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"D\u2019Arienzo, L., Acierno, S., Patti, A., and Di Maio, L. (2024). Cellulose\/Polyhydroxybutyrate (PHB) Composites as a Sustainable Bio-Based Feedstock to 3D-Printing Applications. Materials, 17.","DOI":"10.3390\/ma17040916"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"4801","DOI":"10.1007\/s10924-023-02835-9","article-title":"Green bionanocomposites based on polyhydroxybutyrate and filled with cellulose nanocrystals: Melting processing and characterization","volume":"31","author":"Schmidt","year":"2023","journal-title":"J. Polym. Environ."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Zhang, B., Huang, C., Zhao, H., Wang, J., Yin, C., Zhang, L., and Zhao, Y. (2019). Effects of cellulose nanocrystals and cellulose nanofibers on the structure and properties of polyhydroxybutyrate nanocomposites. Polymers, 11.","DOI":"10.3390\/polym11122063"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"7159","DOI":"10.15376\/biores.15.3.7159-7177","article-title":"Characterization of poly-hydroxybutyrate\/luffa fibers composite material","volume":"15","year":"2020","journal-title":"BioResources"},{"key":"ref_24","unstructured":"(1992). Solvent Extractives of Wood and Pulp (Standard No. TAPPI T204)."},{"key":"ref_25","first-page":"55","article-title":"Cellulose and hemicellulose","volume":"Volume 2","author":"Libby","year":"1962","journal-title":"Pulp and Paper Science and Technology"},{"key":"ref_26","unstructured":"(1999). Alpha-, Beta- and Gamma-Cellulose in Pulp (Standard No. TAPPI T203 OS-71)."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1173","DOI":"10.1021\/acs.langmuir.0c03061","article-title":"Nanofibrous foams of poly (3-hydroxybutyrate)\/cellulose nanocrystal composite fabricated using nonsolvent-induced phase separation","volume":"37","author":"Choi","year":"2021","journal-title":"Langmuir"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Frone, A.N., Panaitescu, D.M., Gabor, A.R., Nicolae, C.-A., Ghiurea, M., and Bradu, C. (2024). Poly(3-hydroxybutyrate) Modified with Thermoplastic Polyurethane and Microfibrillated Cellulose: Hydrolytic Degradation and Thermal and Mechanical Properties. Polymer, 16.","DOI":"10.3390\/polym16243606"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"102487","DOI":"10.1016\/j.coco.2025.102487","article-title":"Enhancement of thermal and mechanical Properties: Nanofibrillated cellulose-reinforced PHB\/PBAT 3D printing filaments for fused deposition modeling","volume":"57","author":"Jeffri","year":"2025","journal-title":"Compos. Commun."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1552","DOI":"10.1016\/j.progpolymsci.2012.04.003","article-title":"Biocomposites reinforced with natural fibers: 2000\u20132010","volume":"37","author":"Faruk","year":"2012","journal-title":"Prog. Polym. Sci."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Zhou, Y., Li, Y., Li, D., Yin, Y., and Zhou, F. (2022). Electrospun PHB\/chitosan composite fibrous membrane and its degradation behaviours in different pH conditions. J. Funct. Biomater., 13.","DOI":"10.3390\/jfb13020058"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Adnan, M., Siddiqui, A.J., Ashraf, S.A., Snoussi, M., Badraoui, R., Ibrahim, A.M., and Patel, M. (2023). Characterization and process optimization for enhanced production of polyhydroxybutyrate (PHB)-based biodegradable polymer from Bacillus flexus isolated from municipal solid waste landfill site. Polymers, 15.","DOI":"10.3390\/polym15061407"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1178","DOI":"10.1016\/j.psep.2024.05.021","article-title":"Biosynthesis of bioplastic polyhydroxybutyrate (PHB) from microbes isolated from paddy\/sugarcane fields and fabrication of biodegradable thin film","volume":"187","author":"Balasubramanian","year":"2024","journal-title":"Process Saf. Environ. Prot."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"107005","DOI":"10.1016\/j.polymertesting.2020.107005","article-title":"Glycerol-based additives of poly (3-hydroxybutyrate) films","volume":"93","author":"Quispe","year":"2021","journal-title":"Polym. Test."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1016\/0032-3861(73)90087-6","article-title":"Structural studies of polyesters: 5. Molecular and crystal structures of optically active and racemic poly (\u03b2-hydroxybutyrate)","volume":"14","author":"Yokouchi","year":"1973","journal-title":"Polymer"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Frone, A.N., Nicolae, C.A., Eremia, M.C., Tofan, V., Ghiurea, M., Chiulan, I., and Panaitescu, D.M. (2020). Low molecular weight and polymeric modifiers as toughening agents in poly (3-hydroxybutyrate) films. Polymers, 12.","DOI":"10.3390\/polym12112446"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"de Sousa Junior, R.R., Dos Santos, C.A.S., Ito, N.M., Suqueira, A.N., Lackner, M., and Dos Santos, D.J. (2022). PHB processability and property improvement with linear-chain polyester oligomers used as plasticizers. Polymers, 14.","DOI":"10.3390\/polym14194197"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"449","DOI":"10.1016\/j.ijbiomac.2022.07.072","article-title":"Polyhydroxybutyrate (PHB) produced from red grape pomace: Effect of purification processes on structural, thermal and antioxidant properties","volume":"217","author":"Etxabide","year":"2022","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"536","DOI":"10.1016\/j.progpolymsci.2012.06.003","article-title":"The chemomechanical properties of microbial polyhydroxyalkanoates","volume":"38","author":"Laycock","year":"2013","journal-title":"Prog. Polym. Sci."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1927","DOI":"10.1007\/s10570-023-05719-2","article-title":"Nonwoven materials based on natural and artificial fibers","volume":"31","author":"Makarov","year":"2024","journal-title":"Cellulose"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1011","DOI":"10.1007\/s10570-018-1653-2","article-title":"Comparative study of cellulosic components isolated from different Eucalyptus species","volume":"25","author":"Carrillo","year":"2018","journal-title":"Cellulose"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"43","DOI":"10.5552\/drind.2018.1737","article-title":"The effect of nanoboron nitride on some properties of biopolymer nanocomposites with cellulose nanofibrils and nanoclays","volume":"69","author":"Al","year":"2018","journal-title":"Drv. Ind."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"743","DOI":"10.1007\/s00396-012-2784-x","article-title":"Influence of microcrystalline cellulose fiber (MCCF) on the morphology of poly (3-hdyroxybutyrate) (PHB)","volume":"291","year":"2013","journal-title":"Colloid Polym. Sci."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"6969","DOI":"10.1016\/j.jmrt.2025.04.320","article-title":"Influence of babassu fiber content on the chemical, physical and mechanical properties of polyhydroxybutyrate\/babassu biocomposites","volume":"36","author":"Gerardo","year":"2025","journal-title":"J. Mater. Res. Technol."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Vahabi, H., Michely, L., Moradkhani, G., Akbari, V., Cochez, M., Vagner, C., Renard, E., Saeb, M.R., and Langlois, V. (2019). Thermal Stability and Flammability Behavior of Poly(3-hydroxybutyrate) (PHB) Based Composites. Materials, 12.","DOI":"10.3390\/ma12142239"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"e20240521","DOI":"10.1590\/1980-5373-mr-2024-0521","article-title":"Polyhydroxybutyrate\/Mica Biocomposites: Influence of Filler Content on the Thermal and Mechanical Properties of PHB","volume":"28","author":"Bastos","year":"2025","journal-title":"Mater. Res."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1007\/s10973-019-09106-7","article-title":"Evaluation of thermal properties of zirconium\u2013PHB composites","volume":"143","author":"Tavares","year":"2021","journal-title":"J. Therm. Anal. Calorim."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1186\/s40643-021-00361-x","article-title":"Optimization of cultivation medium and cyclic fed-batch fermentation strategy for enhanced polyhydroxyalkanoate production by Bacillus thuringiensis using a glucose-rich hydrolyzate","volume":"8","author":"Singh","year":"2021","journal-title":"Bioresour. Bioprocess."}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/18\/8\/997\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,22]],"date-time":"2026-04-22T04:20:00Z","timestamp":1776831600000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/18\/8\/997"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,20]]},"references-count":48,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2026,4]]}},"alternative-id":["polym18080997"],"URL":"https:\/\/doi.org\/10.3390\/polym18080997","relation":{},"ISSN":["2073-4360"],"issn-type":[{"value":"2073-4360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,20]]}}}